JP7399970B2 - wire rope - Google Patents

Description

The present invention relates to a wire rope impregnated with a grease composition that has little impact on the environment and has anti-rust properties against salt water.

In recent years, there has been increasing interest in protecting water resources and the marine environment. For example, in the United States, all ships entering port are installing biodegradable, biodegradable, Vessel General Permits (VGPs) have been enacted that require the use of Environmentally Acceptable Lubricants (EALs) that are non-toxic and non-bioaccumulative. Under these circumstances, there is an urgent need to develop biodegradable grease for the purpose of preventing pollution of oceans, lakes, rivers, etc.

Patent Document 1 describes a wire rope impregnated with a lubricant that has a low environmental impact, but the biodegradability of the lubricant is not sufficient.

Japanese Patent Application Publication No. 2012-219401

An object of the present invention is to provide a wire rope impregnated with a grease composition that has little impact on the environment and has excellent rust prevention properties against salt water such as seawater.

As a result of extensive studies, the present inventors have discovered that a grease composition containing a biodegradable base oil, a thickener, and a rust preventive agent containing a calcium sulfonate complex and a sorbitan fatty acid ester has been found to be effective against rust in salt water. found that it has excellent properties. Furthermore, the present invention was completed by discovering that a grease composition suitable for manufacturing wire ropes can be obtained by controlling the melting point within a predetermined range.

That is, the present invention provides [1] a wire rope comprising a core and strands twisted around the outer periphery of the core, wherein at least one of the core and the strands is impregnated with a grease composition; The grease composition contains a biodegradable base oil, a thickener, and a rust inhibitor containing a calcium sulfonate complex and a sorbitan fatty acid ester, and the total amount of biodegradable organic substances in the grease composition. A wire rope having a content of 75% by mass or more and a rust preventive content of 2.5 to 30% by mass,
[2] The wire rope according to [1], wherein the content of calcium sulfonate complex relative to sorbitan fatty acid ester (content of calcium sulfonate complex/content of sorbitan fatty acid ester) is 0.5 to 5.0;
[3] The wire rope according to [1] or [2], wherein the grease composition has a melting point of 45 to 100°C;
[4] The wire rope according to any one of [1] to [3], wherein the grease composition further contains a biodegradable wax.
[5] The wire rope according to [4], wherein the content of the biodegradable wax in the total amount of the biodegradable base oil and the biodegradable wax is 5.0 to 40% by mass;
[6] The wire rope according to any one of [1] to [5], wherein the content of the thickener in the grease composition is 1.0 to 25% by mass.
[7] A method for producing a wire rope comprising a core and strands twisted around the outer circumference of the core, the method comprising a biodegradable base oil, a thickener, a calcium sulfonate complex, and a sorbitan fatty acid ester. Grease containing a rust preventive agent containing a rust preventive agent, in which the total content of biodegradable organic substances in the composition is 75% by mass or more, and the content of the rust preventive agent is 2.5 to 30% by mass. A manufacturing method comprising: heating the grease composition to a temperature at which the composition melts; and impregnating at least one of the core and the strands with the grease composition;
[8] The method according to [7], wherein the heating temperature of the grease composition is 50 to 130°C.

The grease composition impregnated into the wire rope of the present invention has little impact on the environment and has excellent rust prevention properties against salt water such as seawater. In addition, because it does not use metal additives such as zinc or molybdenum that are used in general grease, there is a low risk of toxicity and accumulation to living things.

Further, by setting the melting point of the grease composition within a predetermined range, the grease composition can be made suitable for manufacturing wire ropes.

FIG. 1 is a side view (partially unraveled side view) of a wire rope according to an embodiment of the present invention.

A procedure for producing a wire rope, including the preparation of a grease composition, which is an embodiment of the present invention, will be described in detail below. However, the following description is an illustration for explaining the present invention, and is not intended to limit the technical scope of the present invention only to this described range. Note that in this specification, when a numerical range is indicated using "~", the numerical values at both ends thereof are included.

<Grease composition>
The grease composition according to the present embodiment contains a biodegradable base oil, a thickener, a rust preventive agent containing a calcium sulfonate complex and a sorbitan fatty acid ester, and preferably contains a biodegradable wax. The total content of biodegradable organic substances (especially biodegradable base oil, biodegradable wax, and sorbitan fatty acid ester) in the composition is 75% by mass or more. shall be. The above-mentioned VGP is based on the OECD Test Guideline 301 series, which is a standard test method for measuring the ready biodegradability of organic substances, and is based on a predetermined biodegradability level (e.g., based on the OECD Test Guideline 301B, It is specified that the grease composition should contain 75% by mass or more of an organic substance that has a degree of biodegradation by microorganisms of 60% or more. Designed.

(base oil)
As the base oil, base oils that are determined to be biodegradable and have a predetermined degree of biodegradation in accordance with the OECD Test Guideline 301 series are preferably used (hereinafter, in this specification, such base oils will be referred to as (Sometimes referred to simply as "biodegradable base oil.")

Biodegradable base oils include, but are not particularly limited to, vegetable oils, animal oils, synthetic ester oils, polyalkylene glycols, synthetic hydrocarbon oils, etc. From the viewpoints of rust prevention and water resistance, synthetic ester oils and vegetable oils are preferred. is preferred. Furthermore, synthetic ester oils are more preferred from the viewpoint of oxidation stability and storage stability under high temperatures, and vegetable oils are preferred from the viewpoints of cost, high biodegradation rate, and safety such as toxicity and accumulation.

In this specification, "vegetable oil" is an oil derived from plants, and is a concept that includes fats and oils. Vegetable oils that can be used in this embodiment are not particularly limited, but include, for example, cocoa butter, corn oil, peanut oil, sunflower oil, soybean oil, coconut oil, olive oil, camellia oil, safflower oil, oilseed oil, linseed oil, and coconut oil. Oils such as oak oil, almond oil, apricot kernel oil, castor oil, rapeseed oil, large fuse oil, china oil, cottonseed oil, sesame oil, palm oil, palm kernel oil, rice bran oil, tung oil, turpentine oil, kapok oil, etc. , corn oil, sunflower oil, safflower oil, castor oil, linseed oil, soybean oil, rapeseed oil, cottonseed oil, olive oil, camellia oil, tung oil, turpentine oil, coconut oil, and palm oil. Alternatively, a mixture of a plurality of these oils, an oil or fat containing diglyceride or monoglyceride, or an oil that has undergone some modification such as oxidation or reduction may also be used.

Commercially available vegetable oils include, for example, vegetable oils manufactured by Marusho Co., Ltd. such as soybean oil KT; vegetable oils manufactured by Nisshin Oilio Co., Ltd. such as soybean oil and linseed oil; and vegetable oils manufactured by Boso Oil and Fat Co., Ltd. such as rice salad oil. Vegetable oils; Vegetable oils manufactured by Cognis Japan Co., Ltd. such as TEXAPRINTSDCE; Vegetable oils manufactured by Azuchi Sangyo Co., Ltd. such as limonene oil, eucalyptus oil, and paulownia oil; Harima Chemicals such as Hartol SR-20, Hartall SR-30, Hartall R-30, etc. Vegetable oil manufactured by Arakawa Chemical Co., Ltd.; turpentine oil manufactured by Arakawa Chemical Industry Co., Ltd. such as α-pinene, Toyo Shojirushi, and Dipentene; industrial No. 1 castor oil manufactured by Toyokuni Oil Co., Ltd., etc., but limited to these. It is not something that will be done.

As used herein, "animal oil" refers to oil derived from animals, and is a concept that includes fats and oils. Examples of animal oils that can be used in this embodiment include fish oils obtained from fish bodies such as sardine oil, mackerel oil, herring oil, saury oil, tuna oil, and cod liver oil; lard fat, chicken fat, butter fat, beef tallow, and beef bone fat. , deer tallow, dolphin tallow, horse tallow, pork tallow, bone oil, mutton tallow, cow leg oil, porpoise oil, shark oil, sperm whale oil, whale oil, etc., selected from the group consisting of fish oil, beef tallow, and pork tallow. It is preferable to use one or more oils that contain a mixture of these oils, oils and fats containing diglycerides and monoglycerides, and oils that have been partially modified by oxidation, reduction, etc.

As the synthetic ester oil, fatty acid diesters and fatty acid polyol esters are preferably used, and fatty acid polyol esters are more preferred. Specific examples of fatty acid diesters include diisodecyl adipate, diisodecyl azelaate, dioctyl sebacate, and the like. Specific examples of fatty acid polyol esters include neopentyl glycol diester, trimethylolpropane triester, trimethylolpropane complex ester, pentaerythritol tetraester, dipentaerythritol hexaester, and the like. Among them, Synative ES TMP 05/140 and 05/320 (trimethylolpropane complex ester) manufactured by BASF Japan Co., Ltd., Priorolube 2089 (trimethylolpropane oleate) manufactured by Croda Japan Co., Ltd., and Ito Oil Co., Ltd. Highly biodegradable ester oil such as MINERASOL LB-601 (special castor oil-based condensed fatty acid ester) is preferably used.

Examples of the polyalkylene glycol include polyethylene glycol, polypropylene glycol, polyethylene oxide-propylene oxide (a copolymer of ethylene oxide and propylene oxide), poly(methyl-ethylene) glycol, polybutylene glycol, and the like. Further, as the polyalkylene glycol, any of random copolymers, alternating copolymers, block copolymers, and mixtures thereof of polyalkylene glycols obtained using two or more different alkylene oxides can be used.

Examples of the synthetic hydrocarbon oil include FT synthetic oil. In this specification, "FT synthetic oil" is obtained by applying the Fischer-Tropsch (FT) reaction to a mixed gas (sometimes referred to as synthesis gas) containing hydrogen and carbon monoxide as main components. Liquid fractions equivalent to naphtha, kerosene, and gas oil, hydrocarbon mixtures obtained by hydrorefining and hydrocracking these, and liquid fractions and FT wax produced by FT reaction, which are hydrorefined, It means a synthetic oil consisting of a hydrocarbon mixture obtained by hydrocracking. Note that FT synthetic oils are often named according to their raw materials; for example, those made from natural gas are called GTL, those made from coal are called CTL, and those made from biomass are called BTL. Called.

The biodegradable base oils listed above may be used alone or in combination of two or more. Preferred base oils include one or more synthetic ester oils or a base oil obtained by mixing these with one or more vegetable oils. By using two or more kinds of biodegradable base oils in combination, improvement in lubricity can be expected.

The content of the biodegradable base oil in the grease composition is preferably 60% by mass or more, more preferably 65% by mass or more, more preferably 70% by mass or more, even more preferably 75% by mass or more, and 80% by mass. % or more is particularly preferred.

In addition, the base oil is a normal base oil used in grease compositions to improve lubricity, etc., and is determined to not have the specified biodegradability in accordance with the OECD Test Guideline 301 series. A base oil may also be used. However, in accordance with the OECD Test Guideline 301 series, the total amount of organic substances having a predetermined biodegradability in the grease composition must be less than 25% by mass.

The flash point of the base oil is preferably 230°C or higher, more preferably 260°C or higher. Since the base oil has a flash point of 230° C. or higher, the grease composition is less likely to catch fire. In addition, in this embodiment, the flash point of the base oil can be calculated by the Cleveland open equation (COC) of JIS K 2265 4.

The kinematic viscosity (40° C.) of the base oil is preferably 70 mm ² /s or more, more preferably 90 mm ² /s or more. Further, the kinematic viscosity (40° C.) of the base oil is preferably 1000 mm ² /s or less, more preferably 600 mm ² /s or less. When the kinematic viscosity of the base oil is within the above range, the flash point of the base oil is easily maintained at a high temperature, and the grease composition has good fluidity (pumpability). Note that in this embodiment, the kinematic viscosity of the base oil can be calculated according to JIS K 2283.

(thickener)
The thickener that can be used in this embodiment is not particularly limited, and thickeners commonly used in lubricating greases, such as polybutene, polyisobutene, polyisobutylene, and α-olefin copolymers, can be appropriately selected. The thickener may be a thickener that is determined to be biodegradable (for example, polyisobutylene, etc.) and has a predetermined degree of biodegradability in accordance with the OECD Test Guideline 301 series.

The content of the thickener in the grease composition is preferably 1.0% by mass or more, more preferably 3.0% by mass or more, even more preferably 5.0% by mass or more, and particularly preferably 7.0% by mass or more. Further, the content of the thickener is preferably 25% by mass or less, more preferably 20% by mass or less, even more preferably 15% by mass or less, and particularly preferably 12% by mass or less. When the content of the thickener is within the above range, there is an advantage that adhesion is improved without affecting pumpability.

(anti-rust)
As the rust preventive agent in this embodiment, calcium sulfonate complex and sorbitan fatty acid ester are preferably used. A synergistic antirust effect can be obtained by using calcium sulfonate complex and sorbitan fatty acid ester together.

Calcium sulfonate complex consists of calcium sulfonate, (i) calcium carbonate, (ii) higher fatty acid calcium salts such as calcium dibehenate, calcium distearate, calcium dihydroxystearate, and (iii) lower fatty acid calcium salts such as calcium acetate. , (iv) a calcium salt (calcium soap) selected from calcium borate and the like. Among these, those containing calcium sulfonate and calcium carbonate as essential components, and containing at least two selected from the group consisting of calcium dibehenate, calcium distearate, calcium dihydroxystearate, calcium borate, and calcium acetate. preferable. Specific examples of calcium sulfonate complexes include those commercially available under trade names such as Daphne Multirex WR manufactured by Idemitsu Kosan Co., Ltd., RENOLIT CXI 1 manufactured by Fuchs Japan Co., Ltd., and Calforex EP manufactured by Nippeco Co., Ltd. Some examples include:

Further, from the viewpoint of thickening effect, the calcium sulfonate preferably has a base value of 50 mgKOH/g or more and 500 mgKOH/g or less, more preferably 300 mgKOH/g or more and 500 mgKOH/g or less. Specifically, dialkylbenzenesulfonic acid calcium salts are particularly preferred.

Examples of sorbitan fatty acid esters include sorbitan monooleate, sorbitan trioleate, sorbitan monolaurate, sorbitan tristearate, sorbitan monostearate, sorbitan monopalmitate, polyoxyethylene sorbitan monolaurate, and polyoxyethylene sorbitan monolaurate. Examples include oleate, polyoxyethylene sorbitan monostearate, and the like. As the sorbitan fatty acid ester, for example, sorbitan fatty acid ester commercially available from Kao Corporation under the trade name Emazol, etc. can be used. Note that sorbitan fatty acid ester is an organic substance that is biodegradable in accordance with the OECD Test Guideline 301 series. In particular, since sorbitan monooleate is a substance specified by the regulation "FDA21CFR178.3570," it is highly safe for the human body as long as the prescribed values are observed. The sorbitan fatty acid ester preferably has a saponification value of 145 to 160 and a hydroxyl value of 193 to 210. When the saponification value and hydroxyl value are outside the range of 193 to 210, it becomes difficult to ensure safety as a food ingredient. Note that sorbitan fatty acid ester is an organic substance that is biodegradable in accordance with the OECD Test Guideline 301 series. In particular, since sorbitan monooleate is a substance specified by the regulation "FDA21CFR178.3570," it is highly safe for the human body as long as the prescribed values are observed. The sorbitan fatty acid ester preferably has a saponification value of 145 to 160 and a hydroxyl value of 193 to 210. When the saponification value and hydroxyl value are outside the range of 193 to 210, it becomes difficult to ensure safety as a food ingredient.

The content of calcium sulfonate complex relative to sorbitan fatty acid ester (content of calcium sulfonate complex/content of sorbitan fatty acid ester) is preferably in the range of 0.5 to 5.0, more preferably in the range of 0.7 to 3.0. It is preferably in the range of 1.0 to 2.0, more preferably in the range of 1.0 to 2.0. When it is less than 0.5 or more than 5.0, the synergistic effect of rust prevention tends to be weakened.

The rust inhibitor may appropriately contain other rust inhibitors other than the calcium sulfonate complex and sorbitan fatty acid ester. Examples of other rust preventive agents include sulfonate salts, carboxylic acids, carboxylate salts, ester rust preventive agents, and amine rust preventive agents. As for the other rust preventives, any one of the above-mentioned examples may be used alone, or two or more kinds may be used in combination.

Sulfonic acid salts include sulfonic acid metal salts such as sulfonic acid alkali metal salts and sulfonic acid alkaline earth metal salts, sulfonic acid amine salts, and the like. Sulfonic acid salts may be prepared by reacting alkali metals, alkaline earth metals or amines with sulfonic acids.

As the sulfonic acid constituting the sulfonate, petroleum sulfonic acid and dinonylnaphthalene sulfonic acid are preferred. Examples of the alkali metal constituting the sulfonate include sodium, potassium, and the like. Examples of alkaline earth metals include magnesium, calcium, barium, and the like. Among these, as the metal salt, sodium salt, potassium salt, calcium salt, or barium salt is preferable, and calcium salt is more preferable. Furthermore, when the sulfonate is an amine salt, examples of the amine include monoamines, polyamines, alkanolamines, and the like.

Among the sulfonates, it is preferable to include amine sulfonate, calcium sulfonate, or barium sulfonate, more preferably to include calcium sulfonate, and even more preferably to include petroleum sulfonate calcium salt. In addition, as for the sulfonate salt, any one type from the above-mentioned examples may be used alone, or two or more types may be used in combination.

Examples of the carboxylic acid include monocarboxylic acids such as stearic acid, alkylsuccinic acids and derivatives thereof, alkenylsuccinic acids and derivatives thereof, naphthenic acid, abietic acid, and lanolin fatty acids. Examples of carboxylic acid salts include the metal salts of carboxylic acids (calcium, barium, magnesium, aluminum, zinc, lead, etc.) described above.

Examples of the ester rust preventive include carboxylic acid partial esters such as polyoxyethylene laurate, polyoxyethylene oleate, polyoxyethylene stearate, pentaerythritol monooleate, and succinic acid half ester. Ester-based rust inhibitors have good biodegradability and are therefore preferably used.

Examples of the amine rust preventive include amine derivatives such as alkoxyphenylamine, dibasic carboxylic acid partial amides, and the like.

The content of the rust preventive agent in the grease composition is 2.5% by mass or more, preferably 3.0% by mass or more, and more preferably 4.0% by mass or more. When the content of the rust preventive agent is less than 2.5% by mass, the rust preventive property against salt water tends to decrease. On the other hand, from the viewpoint of reducing non-biodegradable organic substances, the content of the rust inhibitor is 30% by mass or less, preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less. preferable.

(wax)
As the wax, a wax that is determined to be biodegradable and has a predetermined degree of biodegradation in accordance with the OECD Test Guideline 301 series is suitably used (hereinafter, in this specification, such wax will be simply referred to as "biodegradable"). (sometimes described as "degradable wax"). The biodegradable wax can be used as a substitute for a thickener, and can be included in an appropriate amount to adjust the melting point of the grease composition described below.

As the biodegradable wax, known plant waxes, animal waxes, petroleum waxes, and the like can be used. Examples of vegetable waxes include rice wax, carnauba wax, and candelilla wax. Examples of animal waxes include beeswax, lanolin, spermaceti, and the like. Examples of petroleum waxes include microcrystalline wax and paraffin wax. Furthermore, even synthetic waxes that are biodegradable can be used.

The total content of the biodegradable base oil and the biodegradable wax in the grease composition is preferably 60% by mass or more, more preferably 65% by mass or more, more preferably 70% by mass or more, and 75% by mass. % or more is more preferable, and 80 mass % or more is particularly preferable.

The content of biodegradable wax in the total amount of biodegradable base oil and biodegradable wax is preferably 5.0% by mass or more, more preferably 6.0% by mass or more, and 7. The content is more preferably .0% by mass or more, particularly preferably 10% by mass or more. Further, the content is preferably 40% by mass or less, more preferably 35% by mass or less, even more preferably 30% by mass or less, and particularly preferably 25% by mass or less.

(Other ingredients)
The grease composition of this embodiment may contain components (other components) other than the above-mentioned base oil, thickener, rust preventive, and wax as long as the effects of this embodiment are not impaired. The other components mentioned above are not particularly limited, and include, for example, thickeners, anti-wear agents, antioxidants, extreme pressure additives, dyes, hue stabilizers, structural stabilizers, metal deactivators, and viscosity index improvers. etc.

When a thickener is contained, examples of the thickener include metal soaps such as lithium soap, calcium soap, sodium soap, aluminum soap, lithium complex soap, calcium complex soap, and aluminum complex soap, urea compounds, and sodium terephthalate. mate, polytetrafluoroethylene (PTFE), organic bentonite, silica gel, etc., but lithium soap is preferably used from the viewpoint of having no major drawbacks and having a good balance of performance (e.g., water resistance, shear stability, etc.). .

When a thickener (especially aluminum composite soap) is contained, its content is preferably less than 1.0% by mass in the grease composition, more preferably less than 0.5% by mass, and even more preferably less than 0.1% by mass. , it is particularly preferable not to contain a thickener. If the thickener content is 1.0% by mass or more, repeating heating and melting and cooling will cause the grease to soften, oil separate, etc., making it impossible to maintain its original state as a grease, and the additives will deteriorate. There is a risk that rust prevention properties will decrease. It is preferable not to contain aluminum composite soap.

When an anti-wear agent is contained, examples of the anti-wear agent include methylene bisdithiocarbamate, a sulfur-based anti-wear agent, a phosphorus-based anti-wear agent, and the like. As the anti-wear agent, any one of the above-mentioned examples may be used alone, or two or more types may be used in combination. Note that the grease composition of this embodiment can exhibit excellent wear resistance even when no antiwear agent is blended.

Phosphorous anti-wear agents include phosphites such as tributyl phosphite and trioleyl phosphite; phosphates such as tricresidyl phosphate and dilauryl acid phosphate; dibutyloctylamine phosphate salts and amine phosphates such as dilauryl octylamine phosphate; phosphorothionates such as triphenylphosphorothionate and alkylated phosphorothionate; solid lubricants such as calcium phosphate and diphenyl hydrogen phosphite.

When an anti-wear agent is contained, the content of the anti-wear agent is not particularly limited. For example, the antiwear agent is preferably 0.1% by mass or more, more preferably 0.5% by mass or more in the grease composition. Moreover, the anti-wear agent is preferably 5% by mass or less, more preferably 3% by mass or less. When the content of the antiwear agent is within the above range, the resulting grease composition can be provided with excellent wear resistance.

When an antioxidant is contained, examples of the antioxidant include amine antioxidants and the like. The amine antioxidant is preferably an aromatic amine compound. Examples of the aromatic amine compound include diphenylamine, alkylated diphenylamine, phenothiazine, N-phenyl-α-naphthylamine, p,p'-diaminodiphenylmethane, aldol-α-naphthylamine, p-dodecylphenyl-1-naphthylamine, and the like.

When an antioxidant is contained, the content of the antioxidant is not particularly limited. For example, the antioxidant is preferably 0.1% by mass or more, more preferably 0.5% by mass or more in the grease composition. Moreover, the antioxidant is preferably 5% by mass or less, more preferably 3% by mass or less. When the content of the antioxidant is within the above range, the resulting grease composition can be provided with excellent oxidative stability.

When an extreme pressure additive is contained, examples of the extreme pressure additive include molybdenum dithiocarbamate, molybdenum dithiophosphate, thiophosphoric acid ester, sulfurized oil, dibenzyl sulfide, dibutyl disulfide, and the like. Among these, sulfurized fats and oils are preferred. As the extreme pressure additive, any one of the above-mentioned examples may be used alone, or two or more types may be used in combination.

When an extreme pressure additive is contained, the content of the extreme pressure additive is not particularly limited. For example, the extreme pressure additive is preferably 0.1% by mass or more, more preferably 0.5% by mass or more in the grease composition. Moreover, the extreme pressure additive is preferably 5% by mass or less, more preferably 3% by mass or less. When the content of the extreme pressure additive is within the above range, the resulting grease composition can be provided with excellent load resistance.

The melting point of the grease composition is preferably 45°C or higher, more preferably 50°C or higher, even more preferably 55°C or higher, and particularly preferably 60°C or higher, from the viewpoint of preventing the grease from dripping from the wire rope. In addition, the melting point of the grease composition is preferably 100°C or lower, more preferably 95°C or lower, and 90°C or lower, from the viewpoint of preventing deterioration of the grease composition and preventing difficulty in application on the wire rope manufacturing line. The temperature below is more preferable, and 85°C or below is particularly preferable.

The grease composition according to the present embodiment has low bioconcentration and is safe for the human body even if it accidentally leaks into the ocean or river. It also has rust prevention, water resistance, water repellency, and adhesion properties that are comparable to or better than industrial lubricants.

<Wire rope>
FIG. 1 is a side view (partially unraveled side view) of a wire rope according to an embodiment of the present invention. The wire rope 1 includes a core rope 2 and strands 3 twisted around the outer circumference of the core rope. Further, at least one of the core cord and the strand is impregnated with a grease composition.

The core rope 2 is made by twisting together a plurality of wires 21 made of metal (for example, steel), synthetic resin fiber (for example, polypropylene, polyester, polyethylene, etc.), or vegetable fiber (for example, hemp, etc.). The grease composition may be impregnated with pressure, heat, or pressure and heat when the plurality of wires 21 are twisted together, or the grease composition may be impregnated with the grease composition after the plurality of wires 21 are twisted together. Good too. The heating temperature is not particularly limited as long as it is a temperature at which the grease composition melts, but is usually in the range of 50 to 130°C, preferably 70 to 100°C.

The strand 3 is formed by twisting together a plurality of metal wires 31 (eg, steel). A plurality of the strands 3 are usually twisted around the outer periphery of the core rope 2. The grease composition may be impregnated with pressure, heat, or pressure and heat when the plurality of wires 31 are twisted together, or the grease composition may be impregnated with the grease composition after the plurality of wires 31 are twisted together. Good too. The heating temperature is not particularly limited as long as it is a temperature at which the grease composition melts, but is usually in the range of 50 to 130°C, preferably 70 to 100°C.

The wire rope according to the present embodiment has excellent rust prevention properties against saltwater such as seawater, so it can be used for wire ropes for ships such as mooring ropes, boat falls, guy ropes, towing ropes, cargo falls, and topping lifts; Suitable as wire ropes for fisheries such as trawl lines and purse seine ring lines; wire ropes that come into contact with water such as wire ropes for water gates; also suitable as wire ropes for cranes used on quays such as unloaders and gantry cranes. used for.

The corrosion resistance of the wire rope according to the present embodiment can be evaluated, for example, by a salt spray test described in JIS Z 2371:2015.

Hereinafter, the present invention will be explained in more detail with reference to Examples. The present invention is not limited to these examples at all.

Various materials used in Examples and Comparative Examples are listed below.
Synthetic ester oil: Synative ES TMP 05/320 (trimethylolpropane complex ester, kinematic viscosity (40°C): 326 mm ² /s) manufactured by BASF Japan Co., Ltd.
Wax: Paraffin Wax 155F manufactured by Nippon Seiro Co., Ltd.
Thickener: Idemitsu Polybutene 2000H manufactured by Idemitsu Kosan Co., Ltd.
Calcium sulfonate complex: Daphne Multirex WR manufactured by Idemitsu Kosan Co., Ltd.
Sorbitan fatty acid ester 1: Emazol O-10V (Sorbitan monooleate) manufactured by Kao Corporation
Sorbitan fatty acid ester 2: Emazol O-30V (sorbitan trioleate) manufactured by Kao Corporation

(Examples 1 to 8 and Comparative Examples 1 to 4)
Grease compositions were prepared according to the formulations listed in Table 1. The obtained grease composition was evaluated as follows. The evaluation results are shown in Table 1.

<Measurement of melting point>
The melting point of the grease composition was measured in accordance with JIS K 2235.

<Neutral salt spray test>
In accordance with JIS K 2246 6.35, a test piece coated with a test grease composition (coating method compliant with JIS K 2220 21) was placed in a device sprayed with neutral salt water in an environment of 35°C. The degree of rust occurrence after holding for a period of time was examined. Table 1 shows the salt water spraying times at which the degree of rust occurrence was 0%. The performance target value is 240 hours or more.

From the results in Table 1, it can be seen that the grease composition impregnated into the wire rope of the present invention has excellent rust prevention properties against salt water.

<Production of wire rope>
The core rope 2 was made of 49 steel wires 21 twisted together, and the strand 3 was made of 36 steel wires 31 twisted together. The grease composition was applied to the core rope 2 and the strand 3, which were prepared by twisting wires together, by heating and melting the grease composition at 80° C. with a heater. Thereafter, six strands 3 impregnated with the grease composition were twisted around the outer circumference of the core rope 2 to produce a wire rope.

A wire rope impregnated with the grease composition of the present invention has less impact on the environment and has excellent rust prevention properties against salt water such as seawater, and is therefore particularly useful as a wire rope that comes into contact with water.

1 Wire rope 2 Core rope 3 Strand 21 Element wire (core rope)
31 Strand

Claims (7)

A wire rope comprising a core and strands twisted around the outer circumference of the core,
at least one of the core rope and the strand is impregnated with a grease composition;
The grease composition contains a biodegradable base oil, a thickener, and a rust inhibitor containing a calcium sulfonate complex and a sorbitan fatty acid ester,
The melting point of the grease composition is 45 to 100°C,
The total content of biodegradable organic substances in the grease composition is 75% by mass or more,
A wire rope characterized in that the content of a rust preventive agent is 2.5 to 30% by mass. The wire rope according to claim 1, wherein the content of calcium sulfonate complex relative to sorbitan fatty acid ester (content of calcium sulfonate complex/content of sorbitan fatty acid ester) is 0.5 to 5.0. The wire rope according to claim 1 or 2 , wherein the grease composition further contains a biodegradable wax. The wire rope according to claim 3 , wherein the content of the biodegradable wax in the total amount of the biodegradable base oil and the biodegradable wax is 5.0 to 40% by mass. The wire rope according to any one of claims 1 to 4 , wherein the content of the thickener in the grease composition is 1.0 to 25% by mass. A method for manufacturing a wire rope comprising a core and strands twisted around the outer circumference of the core,
The composition contains a biodegradable base oil, a thickener, and a rust inhibitor containing a calcium sulfonate complex and a sorbitan fatty acid ester, and the total content of biodegradable organic substances in the composition is 75% by mass. The above, the step of heating the grease composition to a temperature at which the grease composition having a rust preventive content of 2.5 to 30% by mass melts, and at least one of the core and the strands, A manufacturing method including a step of impregnating the grease composition. The manufacturing method according to claim 6 , wherein the heating temperature of the grease composition is 50 to 130°C.

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